fixpt_evenspace_cleanup

Modify breakpoints of lookup table to have even spacing

Syntax

xdata_modified = fixpt_evenspace_cleanup(xdata,xdt,xscale)

Description

xdata_modified = fixpt_evenspace_cleanup(xdata,xdt,xscale) modifies
breakpoints of a lookup table to have even spacing after quantization.
By adjusting breakpoints to have even spacing after quantization, Simulink®
Coder™ generated
code can exclude breakpoints from memory.

xdata is the breakpoint vector of
a lookup table to make evenly spaced, such as 0:0.005:1. xdt is
the data type of the breakpoints, such as sfix(16). xscale is
the scaling of the breakpoints, such as 2^-12.
Using these three inputs, fixpt_evenspace_cleanup returns
the modified breakpoints in xdata_modified.

This function works only with nontunable data and considers
data to have even spacing relative to the scaling slope. For example,
the breakpoint vector [0 2 5], which has spacing value 2 and 3, appears
to have uneven spacing. However, the difference between the maximum
spacing 3 and the minimum spacing 2 equals 1. If the scaling slope
is 1 or greater, a spacing variation of 1 represents a 1-bit change
or less. In this case, the fixpt_evenspace_cleanup function
considers a spacing variation of 1 bit or less to be even.

Modifications to breakpoints can change the numerical behavior
of a lookup table. To check for changes, test the model using simulation,
rapid prototyping, or other appropriate methods.

Examples

Modify breakpoints of a lookup table to have even spacing after
quantization:

This website uses cookies to improve your user experience, personalize content and ads, and analyze website traffic. By continuing to use this website, you consent to our use of cookies. Please see our Privacy Policy to learn more about cookies and how to change your settings.